``You only see your relatives at weddings and wakes,'' says a character in McDermott's delicately nuanced, elegiac and emotionally charged new novel (after That Night ), but the three Dailey children do not realize the significance of the remark until, three days after their beloved Aunt May's wedding, the family reassembles at her funeral. This latter occasion, alluded to throughout the narrative, is the only dramatic incident in this work--and it takes place offstage. Indeed, the story may seem too leisurely and uneventful, until, on completion, the reader experiences the catharsis that good literature provides. This meticulously observed evocation of a close-knit Irish Catholic family is seen through the children's eyes, registering the confusion and dawning knowledge which with youngsters try to understand adult relationships. Two sisters and a brother, they go twice a week with their mother from their home in Long Island to Brooklyn, where their mother's stepmother and three unmarried sisters live. Gradually the children comprehend the personality differences and tensions among the Towne sisters as well as their mother's dissatisfaction with her marriage. Gradually, too, they realize with joy that their middle-aged aunt, a former nun, will marry mailman Fred. In the time frame of one year, McDermott foreshadows and looks back on this event, while creating a world as exact as a documentary film and as lyrically imagined as a poem. A formidably gifted prose stylist, she can make each sentence a bell of sound, a prism of sight. BOMC selection. (Apr.)